M&S says

These classic school plimsolls are a school P.E. kit essential, or just as neat as summer footwear. With a pull on design that lets kids slip them on and off in no time at all, changing for lessons is easy. Flexible and comfortable for running around in the playground or the gym, when these kids' plimsolls need to be refreshed they can simply be added to the wash load, able to be machine washed even at 30 degrees.

* 20% off promotion applies at checkout: 20% off schoolwear. Discount applies at checkout directly. See individual items for details. Offer commences 20th December 00:01am AEDT and ends 3rd February at 23:59pm AEDT at www.marksandspencer.com/nz/ only. Includes T76 schoolwear and selected T72 school shoes. Excludes Coats, Underwear, Socks & Tights, Accessories, School Bags and Stationery. Sale and ongoing offers excluded. Please check relevant delivery terms & conditions online. Cannot be used in conjunction with any other promotion, offer or discount code. Offer subject to availability. Offer does not apply to delivery charges. Any refunds will take into account the discount. M&S reserves the right to reject this offer with reasonable cause. Photography non contractually binding.